It's not the speed. I just did a speed test and it shows as 21.42 Mbps download and 4.33 Mbps upload. Is 4.33 Mbps upload so slow that even if type "hi" in the chat window, it doesn't appear at all, even 30 minutes later? How many bytes does it take to say "hi" If I just wait for a long time and then try, the strange slowness goes and there is no slowness at all.

It's clear to me that the data from the game is not getting sent out to the server for some reason, even though incoming data is being received freely.